Modern ostomy appliances are commonly attached to the body by means of an adhesive wafer, having an opening for the stoma sometimes referred to as a starter hole. The adhesive is laminated between plastics films. The film on one side acts a release liner that is removed by the user prior to fitting to the skin. The film on the other face remains permanently in place to prevent the wafer adhering undesirably to the interior of the appliance. The films are sufficiently stiff to stabilize the shape of the wafer, and to protect the adhesive surface that will, in use, contact the skin.
Ostomy appliances commonly fall into two types, called one-piece and two-piece appliances. In a two-piece appliance, the adhesive wafer forms part of a separate body fitment component that is attached by a releasable coupling. A two-piece appliance permits the body fitment to be separated from the appliance without damage, so that at least one of the components continues to be functionally usable. For example, the body fitment may remain in place on the body, and a replacement pouch appliance mounted in place of a used pouch appliance. Two-piece appliances are preferred by some users as they involve less frequent removal the adhesive wafer, which may be used with several different appliances. In contrast, in a one-piece appliance, the adhesive wafer is permanently attached to the appliance, to the extent that the adhesive wafer cannot easily be separated without risk of damaging the appliance. A one-piece appliance is intended to be used as an integral unit. One-piece appliances are preferred over two-piece appliances by some users for a variety of reasons. The absence of the releasable coupling means that their overall profile on the body is reduced, increasing discretion of the appliance. They are generally more flexible than two-piece appliances. They are also simpler to teach and learn than two-piece appliances, and can be more convenient as a result of the need to keep fewer products available for use. Finally, they are sometimes preferred for hygienic reasons since they tend to be more disposable and so may be changed more frequently.
For both one-piece and two-piece appliance types, proper fit of the wafer around the stoma is critical to proper functioning of the wafer, but can be problematic because most commercially available wafers are not manufactured to the identical size, or shape, of an individual's stoma. The wafer must be modified in some way to adapt it to the stoma, and the modification most frequently performed is to manually cut the wafer opening to try to match the size and shape of the stoma. The starter hole gives the wearer a place to start cutting using scissors. In one form, the edge of the wafer opening should be no more than approximately 0.125 inches from the stoma around its entire periphery, for optimum fitting of the appliance. It is difficult to obtain a cut of such precision, because of the aggressive nature of the adhesive against the scissors, and the compliance of the wafer. An even more precise match around the stoma would be preferable, but of course is even more difficult to achieve.
As mentioned above, the degree of matching of the wafer opening to the stoma shape and size is critical to proper functioning of the wafer. As well as attaching the appliance to the skin, the wafer also protects the peristomal skin from contact by stomal effluent. Protection of peristomal skin is important because effluent in contact with the skin causes rapid and severe skin break down. Stomal effluent contains digestive juices that cause excoriation of skin tissue. In addition to being painful, denuded skin is poorly suited to attachment of subsequent wafers, leading to a degenerative cycle of poor attachment, reduced skin protection, and further worsening of the skin condition. Critical elements of skin protection include secure leak-proof adhesion to peristomal skin, and a proper fit of the wafer around the stoma itself. More specifically with respect to fit, it is critical to closely match the wafer opening to the stoma periphery. If the match is imprecise, then skin will be exposed and vulnerable to attack by effluent.
U.S. Pat. No. 6,840,924 describes an improved ostomy appliance including a moldable adhesive, in which at least a portion of the adhesive can be manually molded by the wearer, to provide a custom fit around the stoma. This alternative way of customizing the wafer offers the prospect of a better fit around the stoma than that obtainable by cutting. The adhesive surface of the wafer is exposed on the non-body-facing side, allowing the rim of the adhesive to be rolled or folded back into adhesive contact with itself on the non-body-facing side to anchor the adhesive in its newly molded shape. The moldable adhesive is described for use in both one-piece and two-piece appliances.
However, the absence of film on the non-body facing side of a moldable wafer prevents more of a problem for a one-piece appliance. This occurs because the adhesive would adhere to the interior of the pouch.
If a non-body side wafer surface of a one-piece pouch has a protective film liner, this appliance has additional problems. The presence of, for example, a pouch permanently attached on the non-body-facing side of the wafer obstructs access to the non-body-facing side for removing the protective film to expose the adhesive surface on the non-body-facing side. Without the film, the adhesive may be vulnerable to adhering undesirably to the pouch wall opposite the wafer. Moreover, the presence of the release liner on the body-facing side of the wafer hinders deformation of the wafer, thereby obstructing moldability. Worse still, the release liner hinders finger access through the starter opening for folding or rolling back the adhesive around the starter opening for shaping the opening. A common size of stoma is 25 mm diameter, and for such a size the starter opening should be slightly smaller. However, if the starter opening is less than 25 mm, it is difficult to comfortably or effectively insert a finger through the starter opening for freely molding the wafer.
In general, it is preferred not to remove the release liner until the final moment prior to adhering the wafer to the peristomal skin. The release liner has an important function in protecting the adhesive from contamination, for example, by skin oils or other contaminants that reduce adhesion strength. The effectiveness of the wafer to adhere optimally to skin, and to protect the skin from attack by stomal effluent, depends to a large extent on the wafer not having been exposed substantially prior to contacting the peristomal skin.
Additionally, the presence of a properly designed release liner can act as a molding tool or aid by providing a surface against which the molding process can be effectively conducted as it offers better control of the final dimensions and shape of the wafer.
The present invention provides surprising solutions to these problems.